As you already are aware, in the case of 'Total Thickness', the spacing between the layers is governed by three parameters - growth ratio, maximum thickness, and number of layers. One quick dirty test to verify your inputs is to change the growth ratio to 1. In this case, all your inflation layers should have a constant thickness. This will give you a good sense of what your average distance between the layers would be. If you are looking for a finer clustering, you should be increasing the number of layers and/or decreasing the maximum thickness value. Here are some tests I ran at my end.
Growth ratio = 1, Max thickness = 1 mm, Number of layers = 30:
Growth rate 1.2, Number of layers 30, total thickness 1 mm:
Because Meshing is trying to cluster near the wall, there spacing between the layers increases away from the wall.
I hope this brings some clarity to your question.